Multiple contact printing machine



Nov. 21, 1967 1.. v. GROVER MULTIPLE CONTACT PRINTING MACHINE Filed 001;. 7, 1964 +.Y Expose third row,evc.--

:0 Ewose second rovuQ ---Expose first row gRise one 5709 'INVENTOR. LY/VDO/V l/. GROVE/q NOV. 21, 1967 1 v, GROVER 3,353,469

MULTIPLE CONTACT PRINTING MACHINE Filed Oct. 7, 1964 4 Sheets-Sheet 2 n n I 76 MM ME I PM 1 LII. f? I I 35 35v 47 50 MM 1, "um 1" H INVENTOR. LY/VDO/V V. GROVE/5 NOV. 21, 1967 v, GROVER 3,353,469

MULTIPLE CONTACT PRINTING MACHINE Filed Oct. '7, 1964 4 Sheets-Sheet 5 Gm. mgljn JTTZ/O H8 Vii any 4 46 E 5 INVENTOR. LY/VDO/V 1/ 6R0 l/ER Nov. 21, 1967 1.. v. GROVER 3,353,469

MULTIPLE CONTACT PRINTING MACHINE Filed Oct. 7, 1964 4 Sheets-Sheet L I INVENTOR.

- LYNDO/V l/ 6R0 1/5? United States Patent 3,353,469 MULTIILE CONTACT PRINTING MACHINE Lyndon V. Grover, 3A9 N. Chevy Chase, Glendale, Ealif. 912% Filed Get. 7, 1964, Ser. No. 4024975 38 Claims. (El. 95-73) ABSTRACT GE THE DISULGSURE A graphic arts step and repeat machine has a table on which an image holder is rectilinearly supported. Adjustable stops are provided to be sequentially actuated to move the image holder by uniform increments in each axis. The table has indicia by which a sensitized workpiece is aligned with respect to the stops. A method is provided by which an image, such as a transparency, is accurately aligned with respect to the image holder.

This invention generally relates to a graphic arts printer and a method of attaching a transparency to an exposure unit and more particularly relates to a manual step and repeat multiple-contact-printing or easel graphic arts printer and a method of properly aligning a transparency on the transparency support surface of an exposure unit thereof.

The present invention provides a method and apparatus to rapidly and accurately print a plurality of images on a sensitized sheet of material, e.g., photosensitive paper and metal sheets. The multiple printing graphic arts printer of the present invention may be effectively utilized by photo-engravers, offset printers, silk screen processors, name plate and dial makers, and photographers. The printer comprises a table with effective means for aligning a sensitized sheet on the table, for providing repeatable movement of an exposure unit, for attaching a transparency to said exposure unit, for braking and maintaining the exposure unit in one of its repeatable positions during the use thereof, and for accurately providing repeatable movement of the exposure unit.

Therefore, it is an object of the present invention to provide an improved multicontact printer.

It is still another object of the present invention to provide a manual graphic arts printer for multicontact printing having accurate X- and Y-axes step and repeat adjusting means.

It is still another object of the present invention to provide a graphic arts printer for manual multicontact printing having manually adjustable means for accurately presetting each step of the printing, and means to hold an exposure unit of the printer in a predetermined printing position.

It is still another object of the present invention to provide a graphic arts printer for multiple contact printing comprising X- and Y-axes-step-moving-means connected to a table having a surface for supporting a sensitized sheet of material, the Y-axis-step-means being movable along the X-axis-step-means, a light source or exposure unit being connected to the Y-axis step means, means connected to the X-axis and Y-axis step means to provide accurate repeatable step movement thereof, brake means to releasably hold the X- and Y-axes step means in their step positions, and resilient means to normally maintain the li ht source above the table surface.

It is still a further object of the present invention to provide a method for aligning a transparency on a translucent surface of a light source.

It is still another object of the present invention to provide a method of using a transparent plate having guide and grid means for aligning a transparency on a Patent-eel Nov. 21,

translucent surface of a light source by centrally attaching a transparency onto an opaque sheet, removing a central portion of the opaque sheet so as to provide a mask extending around the periphery of the transparency and using the transparent plate to align the transparency on the translucent surface with respect to a reference.

Another object of the present invention is to provide a method for masking a light source and aligning a transparency on the light source with respect to a reference means and with the aid of an alignment means. A

Other objects, features, and advantages of the present invention will become apparent to those skilled in the art upon consideration of the following description and accompanying drawings wherein like reference numerals refer to like and corresponding parts.

On the drawings:

FIG. 1 is a perspective view illustrating a graphic arts printer for multiple contact printing constructed in accordance with the principles of the present invention;

FIG. 2 is a top view of the graphic arts printer of FIG. 1;

FIG. 3 is a transverse cross-sectional view, with parts in elevation, of the graphic arts printer taken along line III-III of FIG. 2;

FIG. 4 is a partial longitudinal cross-sectional view, with parts in elevation, of the graphic arts printer taken along line IV-IV of FIG. 2;

FIGURE 5 is a partial transverse cross-sectional view, with parts in elevation, of the graphic arts printer taken along line V-V of FIGURE 2;

FIGURE 6 is a partial transverse cross-sectional view with parts in elevation of the graphic arts printer taken along line VI-VI of FIGURE 2;

FIGURE 7 is a partial transverse cross-sectional View, with parts in elevation, taken along line VI-VI of FIG- URE 2;

FIGURE 8 is a bottom view of an exposure unit of the invention;

FIGURE 9 is a bottom View illustrating one step in a method of image alignment in accordance with the principles of the present invention;

FIGURE 10 is a bottom view showing another step in such method;

FIGURE 11 is still a further bottom view illustrating still a further step in such method;

FIGURE 12 is a partial top elevational view illustrating a step in the method of step and repeat multiple contact printing in accordance with the principles of the pres ent invention;

FIGURE 13 is a partial top elevational view illustrating a further step in the method of step and repeat multiple contact printing;

FIGURE 14 is a top elevational view illustrating still another step in the method of step and repeat multiple cont-act printing;

FIGURE 15 is a side view with parts in elevation illustrating an alignment grid used in combination with the graphic arts printer of the present invention;

FIGURE 16 is a partial side view illustrating an exposure unit of the graphic arts printer of the present invention;

FIGURE 17 illustrates a sensitized sheet of material having a plurality of images thereon and which was manufactured in accordance with the method of the present invention; and

FIGURE 18 is a perspective view illustrating a further exposure unit.

As shown in the drawings:

Referring to FIGURES 1 to 3, there is illustrated a manual multiple contact printing graphic art printer 29. The graphic arts printer comprises a table 21, a fixed rigid guide rail 22, a rigid carriage assembly 23, an exit posure unit support or light source support 24, an exposure unit or light source or image holder 26, a first travel stop block 27, a second travel stop block 28, a first step travel adjusting means 29, a second step travel repeat adjusting means 31, and sensitized sheet-alignmentgrid-indicia 32.

The table 21 includes a substantially rectangular anodized aluminum table top 33, a pair of anodized aluminum angle legs 34 and 36 suitably attached to the table top and extending along opposite sides thereof, and a plurality of angle braces 35 extending between the legs 34 and 36 and suitably connected to the table top by countersunk screws 35a. The table top has a surface 37 adapted to support a sensitized sheet (not shown) and the legs 34 and 36 have suitable rubber boots 34a and 3611 on their respective ends.

The fixed rigid guide rail 22 is generally cylindrical in cross section and has a relatively flat top surface 39 extending for a major portion of the length thereof. The guide rail is rigidly connected to the table top 33 and supported a predetermined distance above the table surface 37 by a plurality of support bars 41. The fixed guide rail 22 extends parallel to one edge of the table and will hereinafter be referred to as extending along the X-axis. A pair of carriage stop washers 42 and 43 are connected by bolts 44 to the ends of the guide rail 22. The stop washer 43 acts as an end limit means as well as a starting reference for the carriage assembly 23.

The rigid carriage assembly 23 comprises a rectangular travel block 46 movably supported on the fixed guide rail 22, a pair of spaced parallel movable guide rails 47 and 48 secured to the travel block and extending therefrom in a direction perpendicular to the direction of the fixed guide rail 22 and which will hereinafter be set forth as extending along the Y-axis, a perpendicular guide plate 49 attached to the other ends of the movable guide rails 47 and 48, and said guide plate 49 having a lower lip 51 extending beneath the table surface 37 and having a roller 50 rotatably connected thereto and extending inwardly therefrom to movably engage the table surface 37 along an edge opposite to said one edge thereof and to support and guide the carriage assembly 23 therealong.

The movable inner guide rail 47 is generally cylindrical in cross section and has a relatively flat top surface 52 extending from the guide plate for a major portion of its length.

Referring also to FIGURE 7, the carriage travel block 46. is a rectangular block 55 having a pair of rectangular end washers 56 and 57 suitably afiixed to the ends thereof and a passage or groove 53 passing axially through the washers and along block bottom surface 54. The fixed guide rail 22 passes through the passage 53 in slightly spaced relation to enable free movement of the block along the fixed guide rail parallel to the X-axis.

Four hard rubber rollers 58 are suitably rotatably connected to the block 55 with their rotational axes extending transversely to the guide rail 22 and at an angle to the table surface. The rollers extend within the travel block 46 and engage the curved surface of the fixed guide rail 22 to support and guide the travel block 46 therealong.

A pair of Allen head screws 59, one of which is also functionally a stop 59, extends axially for a predetermined distance from the travel 'block end washer 56. The functlion of the stop 59 is described hereinafter in greater detai A carriage lock means 62 as illustrated in FIGURE 7, is connected to the block 55 adjacent one end thereof and comprises a threaded vertical passage 61 extending substantially perpendicularly to the block passage 53, a brake shoe counterbore 67 interconnecting the threaded passage and the block passage, a threaded rod 64 threaded into the passage 61 and having a manual turning knob 63. attached to the outer end thereof, and a relatively flat cylindrical br-ake shoe 66 within the counterbore 67 and having one end facing the rod 64 and the other end facing the flat top surface 39 of the fixed guide rail 22. The brake shoe '66 is made of any suitable material such as hardened steel. The brake shoe 66 slidably fits within the counterbore 67 and has a thickness less than the length of the counterbore 67. Thus, when the rod 64 is moved sufficiently towards the guide rail 22, it urges the brake shoe 66 into braking engagement with the rigid guide rail flat surface 39. This braking engagement effectively stationarily locks the carriage onto the rigid guide rail 22.

The base of the washers 56 and 57, the guide plate 49 and roller 50, and the brake shoe 66 and rigid guide rail flat surface 39, all aid in preventing rotational movement of the carriage 23 about the axis of the rigid guide rail 22.

Referring to FIGURES 2 to 5, the light source support 24 comprises a travel block 46 which is identical to the carriage travel block 46 and therefore, the numerals indicating the various portions of the travel block 46 are identical to the numerals indicating the various portions of the travel box 46 except they contain the prime indicia.

The Y-axis travel block 46' comprises four rollers 58', a block lock 62, a pair of rectangular end washers 56 and 57' with the rectangular washer 57 having a pair of Allen head stop members 59 projecting therefrom, and an arcuate passage 53' passing therethrough. The carriage inner guide rail 47 passes through the passage 53 and the travel block 46' is supported thereon by the rollers 58. The lock 62 is operated in the same manner as the lock 62 and therefore has a brake shoe (not shown) that engages the carriage inner guide rail flat surface 52 to lock the travel block 46' thereon.

A U-frame 65 having a pair of spaced parallel rectangular U-frame legs 68 and '69 is suitably attached to the bottom of the vertical travel block 46'. The U-frame legs extend for a predetermined distance along the X-axis perpendicularly away from the carriage outer rail 48. The U-frame legs are spaced apart and above the table surface 37 such that the light source 26 is supported floatingly therebetween. A rod member 71 is suitably attached to the travel block 46 and extends perpendicularly therefrom towards the outer guide rail 48 and movably engages the bottom surface thereof to prevent or limit rocking movement of the travel block 46' about the axis of the rail 47 and to maintain the legs 68 and 69 a predetermined distance above the table surface 37.

A pair of needle bearing guide pins 72 and 73 extends perpendicularly upwardly from the respective U-frame legs 68 and 69. A pair of leaf spring means 74 and 76 are attached respectively to the U-frame legs 68 and 69 by suitable screw means 77. Each of the-leaf springs 68 and 69 has relatively flattened ends 78 and 79 which are adapted to suitably support the light source 26 as will be hereinafter described in greater detail.

Referring to FIGURES 4, 5 and 8, the light source 26 is a rectangular box 85 having a bottom face 80 with a rectangular transparency support surface 81, of suitable translucent glass, spaced inwardly from the edges of the face 80. A suitable light bulb (not shown) is within the light source box and receives its power supply through wires 82 which may be suitably connected to a common communicates with the bulb within the box 26 to assure the operator that exposure has been made.

Two elongated angle guides 87 and 88 are vertically adjustably attached on opposite sides of the box 85 adjacent the. bottom face thereof by screws 89 which pass through elongated slots 91 formed in the angle guide Walls 92. The angle guide walls 93 have circular reference or guide ports 94 with races 95 therein that are slidably receptive of the perpendicular guide pins 72 and 73. The angle guides 87 and 88 may be suitably adjusted on the walls of the light box 85 such that when the light box 85 is placed on the light source support 24 with the bottom surfaces of the angle guide walls 93 engaging the relatively flat ends of the leaf springs 74 and 76 and the guide pins 72 and 73 passing through the guide races 95, the glass transparency support surface 81 is spaced a predetermined distance above the table surface 37 and extends relatively parallel thereto, as illustrated in FIG- URES 4 and 5.

The travel stop blocks 27 and 28 are of identical structure and, therefore, only the travel stop block 27 will be described in detail. Referring to FIGURE 6, the travel stop block 27 has a relatively short length with a cylindrical passage 96 to slidably receive the rigid guide rail 22.

The stop block 27 has a lock 100 comprising a threaded vertical passage 97, a brake shoe counterbore 98 interconnecting the passage 97 and the block passage 96, a cylindrical brake shoe 98a floatably mounted in the counterbore 98 and facing the flat surface of the guide rail 22, and a threaded bolt member 99 threaded into the passage 97 and having an enlarged knob 191 attached to the outer end thereof. Thus, by turning the knob 101, the bolt 99 urges the brake shoe 98 against the guide rail flat surface 39 to lock the block 27 onto the guide rail 22. An Allen head stop member 102 projects from one end of the travel stop block towards the carriage travel block 46 and is engageable with one of the travel block stop members 59. The stops 59 and 162 contact each other to limit the relative movement of the carriage travel block and the carriage travel stop block in one direction.

Likewise, as shown in FIGURE 3, the travel stop block 28 has a lock 100' that locks the block 28 onto the carriage guide rail 47 and an Allen head stop member 1132 projecting from one end thereof towards the light source support travel block 46' and engageable with the stop member 59.

The step travel adjusting means 29 and 31 are identical and, therefore, the description hereinafter will be limited to the step travel adjusting means 29. Referring to FIG- URES 1, 2, and 12 to 14, the step means 29 comprises a bracket 103- extending outwardly from one side of the travel block 46 and having suitably aflixed there-to a rod or bolt 104 that extends therefrom towards the travel stop lock 27 parallel to the rigid guide rail 22. The stop block 27 has an apertured bracket 196 which projects from one side thereof. The bracket aperture 107 is axially aligned with the bolt 104 and the bolt freely passes therethrough. A tubular spacer 108 slidably passes over the end of the bolt 104 and has one end attached to the stop lock bracket 106 and the other end adapted to engage an adjusting wing nut means 109 which may be locked into a predetermined position by a second wing nut 111. The operation of the travel repeat adjusting means is described hereinafter in greater detail.

The alignment-guide-indicia 32 is located adjacent to one corner of the table surface 37 and has a grid 110 so sized and arranged as to enable compensation for various sizes of transparencies, and defining a center reference 112, an X-axis with a plurality of spaced X-axis lines 114, and a Y-axis with a plurality of spaced Y-axis lines 113.

Referring to FIGURES and 15, a rectangular alignment plate 116 of transparent plastic has imprinted or suitably attached thereto a grid 117 having a plurality of lines 118 extending in the Y-axis and a plurality of lines 119 extending in the X-axis with a central diagonal cross 121. The Y-axis lines 118 and X-axis lines 119 are spaced apart the same distance as the alignment grid Y-axis lines 113 and X-axis lines 114. The alignment plate 116 has a width less than the length of the translucent surface 81 and has extending therefrom two perpendicular guide pins 122 which are spaced apart the same distance as the light source support guide pins 72 and 73 and are adapted to slidably pass through the light source angle guide races 95.

The alignment-guide-indicia 32 is located such that when the end of the travel block 46 abuts the reference washer 43 and the end of the travel block 46' abuts the travel block 4-6, the center reference of the translucent surface 81, as determined by the center 121 of the plate grid 117, coincides with the center 112 of the alignment indicia 32. Thus, a workpiece such as a sensitized sheet may be suitably aligned on the table surface 37 by use of the alignment-guide-indicia 32.

In FIG. 18, there is illustrated a light source or image holder 122 which is similar to the light source 26 except that it emits light of much higher intensity, and to this end, it includes a light of the electronic flash type rather than an incandescent light bulb. The electronic flash source 122 has an additional activating means generally indicated at 123 of well known structure which comprises an off switch 124 and an actuation depression switch 126. When the switch 124 is placed in the on position and the electronic flash light source 122 is connected to a suitable source of electric power, the electronic flash light is caused to flash by depressing the switch 126. The light source 122 is precharged after a predetermined nominal amount of time has passed, such time being somewhat less than that needed to index or reset the light source support 24 in a single axis.

As shown in FIG. ll, a transparency and opaque sheet or mask assembly 130 has been attached to the translucent surface 81 of the light source enclosure with the transparency or negative 131 suitably aligned with respect to the reference means and thus also with respect to the alignment grid 11% of the table 21. The mask assembly includes a paper sheet 132 (FIG. 9) of a color which is opaque to the photo-sensitive workpiece, the sheet 132 having a grid 132a with a central right angle cross marking 133 and X-axis and Y-axis grid lines 135 and 136 respectively corresponding to the right angle cross 112 and the X-axis and Y-axis lines of the alignment grid 110 and corresponding to the plate grid 117.

The method of alignment and attachment of the assembly 139 comprises a feature of my invention. This method comprises a number of steps which may best be understood by reference to FIGS. 8-41. The light source enclosure 85 is inverted as shown in FIG. 8 so that the translucent surface 81 extends toward the viewer. This method envisions the providing of an opaque sheet 132, shown in FIG. 9, having a size which substantially covers the translucent surface 81, such sheet 132 having a grid 132a thereon corresponding dimensionally in spacing to the spacing in the easel grid 110. The opaque sheets grid 13 2a includes lines or indicia 135 extending parallel to the X-axis, and a number of lines 136 extending parallel to the Y-axis. Centrally of the grid 132a, there is provided a central or center reference 133 in the nature of a cross.

Either before or after the step of placing the opaque sheet 132 on the translucent surface 81 is performed, the transparent alignment plate 116 is assembled with the light source enclosure 85 as shown in FIG. 10. To this end, the guide means 122 of the alignment plate 116 are manually inserted into the openings of the guide means 95 of the enclosure 85, thereby aligning the plate grid 117 with the guide means 95. Upon sufficient insertion of the alignment plate guide means 122, the opaque sheet 132 at its opposite surfaces engages the translucent surface 81 and the adjacent surface of the alignment plate 116.

With the opaque sheet 132 and the alignment plate 116 arranged as shown in FIG. 10, the transparency 137 is inserted between the opaque sheet 132 and the alignment plate 116 with its emulsion or other image producing means 138 directed toward the viewer. The transparency 137 is then manually moved about in both the X- and Y- axes so that the center of the image registers with the reference cross 121 shown in FIG. 10. (It may be assumed that the transparency image will mask the central cross 133 of the opaque sheet 132.) With the transparency 131 thus aligned, and with the central reference mark 133 also previously centered with respect to the central reference 121, the transparency 131 is manually attached at its periphery to the opaque sheet 132. This is preferably done by means of masking tape 140 which is of a type that is opaque to such frequencies of the light source 26 as will expose the photosensitive sheet. The opaque sheet 132 and the transparency 137, together with the above-mentioned quantity of tape 140 thus joined to comprise an opaque sheet and centered transparency assembly 130.

The sheet and transparency assembly 130 are now removed as a unit from the enclosure 85 and alignment plate 116. The assembly 130 is inverted to enable the further step of removing a central portion 134 of the opaque sheet 132 (including the reference indicia 133). To this end, it is preferred that straight cuts be made parallel to the X- and Y-axes so as to define a rectangular opening, the edges of which surround the outer periphery of the transparency 131 in laterally outwardly spaced relation. This opening is only in the opaque sheet 132 so that the tape 140 which overlaps the peripheral edges or margins of the transparency 131 determines the exact dimensional limits of the zone to be exposed. Since the tape 140 thus serves to mask the limits of the central opening provided in the sheet 132, and since the sheet 132 projects laterally therefrom toward the outer limits of the illuminated translucent surface 81, the actual masking is thus provided by the joint action of the tape 140 and the remaining portion of the opaque sheet 132.

Upon completion of the removing of the central portion 134 of the opaque sheet 132, the assembly 130 is thereafter reinserted manually between the translucent surface 81 and the alignment plate 116 as described before. Thereafter, the assembly 130 is moved about laterally in both the X- and Y-axes to a position in which the remaining portion of the sheet grid 132a is again aligned with the grid 117 of the alignment plate 116. This aligning step must be done carefully, because by this step, the position of the image 138 of the transparency 131 is given its final alignment or location with respect to the guided light source enclosure 85.

Once the remaining portion of the grid 132a has been realigned with the alignment plate grid 117, further tape 140 is manually applied along the entire outer periphery of the opaque sheet 132 to lock or fix the position of the assembly 130 in fixed relation to the enclosure 85, to maintain thereby its alignment, and to seal optically the entire outer periphery of the assembly 130 to the light source enclosure 85. Upon completion of this step, the alignment plate 116 is removed manually from the enclosure 85, thereby completing the alignment method to render the enumerated components arranged in the manner illustrated in FIG. 11.

A variation of the foregoing method includes the step of removing the central portion 134 of the opaque sheet 132'before the sheet 132 is first inserted, such variation in the method enabling the omission of the steps of removing and reinserting the assembly 130.

A further variation of the above method includes the step of initially accurately locating and taping the opaque sheet 132 with its grid 132a in alignment with the alignment plate grid 117. The transparency is then, if necessary, cut to a size slightly larger than the area to be exposed and is placed centrally on the opaque sheet 132, as indicated by its relative position with respect to the reference cross 121. Such positioning delineates a central portion 134 of the opaque sheet 132 which is to be removed, such central portion being that which is overlaid by the transparency 131. If desired, the size of such central opening 134 may slightly exceed the overall size of the transparency. The tape 140 is then applied as a holding means and as a mask in overlying relation to the inner margin of the apertured opaque sheet, and in overlying relation to the outer margin of the transparency 131 in such position 8 as to define the portion of the transparency which is to be exposed to light.

Once the opaque sheet and transparency assembly 130 has been attached and aligned on the enclosure in accordance with the steps of the foregoing method, the printer-easel 20 may be used to expose a photosensitive sheet 139 (FIG. 17) a number of times to provide thereon a plurality of reversed images 141 by means of the following operation. Initially, it is necessary to transfer the dimensional length and width of the exposed portion of the transparency 131 to the stepping travel adjusting means 29, 31, and to position the unexposed photosensitive sheet 139 in the proper position on the table surface In positioning the unexposed sensitized sheet 139, it is desirable not to waste material around its periphery. Assuming that the carriage is positioned to the right as shown in FIGS. 1 and 2, and assuming that the light source support 24 is disposed in abutting relation to the travel block 46 of the carriage 23, it is evident that the light source 26 will overlie the indicia 110. As the reference means 112 of the indicia 110, under this condition, is in direct two-axis alignment with the reference means 133 of the opaque sheet 132, and the cross-type of reference 121 of the alignment type 116, the center of the image 138 is in registration with such reference means 112 on the surface 37. However, it is diflicult or impossible to determine the correct position of the corner of the unexposed sheet 139 unless suitable provision, such as that shown herein, is utilized. Thus, to position the sheet 139 on the surface 37 of the easel top 33, and with reference to FIG. 11, the user notes the distance between the center of the transparency 131 and the adjacent edges of the central tape 140. This distance is represented by a certain number of squares or lines in the grid 132a. The sensitized sheet 139 is then placed in overlying relation to-a portion of the table grid 110 so that the right edge of the sheet is located to the right of the reference means 112 by a distance corresponding to half of the X-axis dimension of the exposed portion of the transparency. Similarly, the lower or forward edge of the sensitized sheet 139 is disposed a distance toward the fixed guide rail 22 corresponding to half of the Y-axis dimension of the exposed portion of the transparency 131. With the sensitized sheet thus accurately positioned, it is fixed in location as by means of suitable pressure-sensitive tape (not shown). The apparatus 20 is now in position to expose the photosensitive sheet 139 to provide that image indicated by the reference numeral 141-1. It is then desired to shift the light source 26 incrementally in a step-by-step manner so as to produce the images 141-2, 3, 4, 5, 6, 7, etc. To accomplish such predetermined shifting or stepping in an accurate manner, the other transfer of dimensions mentioned above is accomplished.

To this end, the X-axis dimension of the exposed portion of the transparency 131 is measured and transferred to the structure shown in FIG. 12, and in particular to the travel stepping adjusting means 29. One facile manner of making this dimensional transfer is to employ conventional inside calipers (not shown). The lock 62. is first tightened to secure the travel block 46 on the rigid rail 22 in engagement with the reference washer or means 43. With the lock nut means 109 retracted to the left, the stop block 27 is moved to a position where the space between the stops 102 and 59 corresponds to the X-axis dimension of the desired exposed portion, a dimension which is clearly readily mechanically transferred by such calipers. With the stop block 27 thus accurately positioned, the lock is also tightened, and the lock nut means 109 is moved to the right and locked in position in engagement with the tubular portion 108 of the stop block 27. Once this has been accomplished, the lock 62 may be 'manually released to enable the carriage having the travel block 46 to move to the left to a position limited by and defined by interengagement between the stops 102 and 59. This movement to the left of the carriage shifts the lock nut means 109 to the left a corresponding amount, and the exposure 141-2 may now be made. This exposure is preferably made with the lock 62 in a tightened position to insure against any reverse movement. Thereafter, the stop block 27 is moved to the left until the portion 108 thereof again engages the lock nut means ltifi, at which position the lock 100 is again tightened, whereupon the travel block 46 may again be shifted to the left as shown in FIG. 13. (The gap defined by the stops 59 and 102 has not been scaled the same as the X-axis dimension in FIG. 11 to minimize the size of illustration.) Thereafter, the stop lock 27 may again be moved to the left as shown in FIG. 14, a procedure which is repeated until the leftmost image Mk has been provided.

By using a substantially identical technique, the travel stepping adjustment means 31, which during the foregoing stepping and exposing has been locked in position against the travel block 46, is indexed away from the travel block 46 by one step, to place thereby the transparency in position to expose the image 141-6. With the Y-axis stepping adjusting mechanism 31 remaining in a locked position, the structure of FIG. 12 is operated in reverse from that described above to place the light source 26 successively and accurately, in reverse order, in the positions previously occupied along the X-axis structure. When the light source 26 reaches its original X-axis position, the Y-axis stepping adjustment means 31 is again indexed by one space.

Attention is invited to the-fact that since the travel block 46 periodically returns to engage the stop means 43, there is no tendency for tolerances to build-up so as to affect the dimensional accuracy in the X-axis of the image 141-11. The foregoing procedure of operation, if desired, may be shown in a rudimentary form as shown on FIG. 2 at 136.

From the structure described above, it is evident that there is a clearance between the upper surface of the photosensitive sheet 139, and the lowest surface of any of the elements described above carried on the lower side of the light source 26. Thus the transparency may be moved about without becoming scratched, and the light source may be moved about without any possible damage to the finish of the sheet 139. However, as the present invention contemplates contact printing for each exposure, a slight manual pressure applied to the upper side of the light source 26 in a downward direction causes the same to move against the force of the leaf springs 74, 76 to a position of engagement with the photosensitive sheet 139. No shift occurs during such vertical movement in the direction of either the X-axis or the Y-axis because of the guiding function of the guide pins 72, 73.

The light source 26 has an intensity such that a few seconds of illumination gives adequate exposure. However, When metal plates are used which have a somewhat slower emulsion speed, by substitution of the light source 122 for the light source as, the exposure time is rendered substantially equivalent.

Typical operation of the disclosed printer is such that an operator may routinely make fifty identical exposures as shown in FIG. 17 on a sheet of photosensitive material in approximately minutes, with each image located with a predetermined accuracy of about 0.002 inch per step. Moreover, the size of each step in each axis is infinitely adjustable within the limits imposed by the size of the machine. Thus photosensitive sheets may be rapidly subjected to repetitive exposure from a single transparency. Attention is invited to the fact that the only settings required are the X-axis dimension and the Y-axis dimension corresponding to each exposed zone, and that the method and apparatus employs no masking film or the masking material on the photosensitive sheet.

The high accuracy of location enables a stack of multiple image sheets to be simultaneously sheared, with the margin remaining constant for all of the individual pieces id thus produced. In that photosensitive metal plate may be directly exposed without the necessity for providing a multiple image negative, a great saving and time and cost is produced where, for example, nameplates are made by this process. A typical exposure time for each image is on the order of one second.

All the various minor modifications might be suggested by those versed in the art, it should be understood that I wish to embody within the scope of the patent warranted hereon, all such embodiments as reasonably and properly come within the scope of my contribution to the art.

I claim as my invention:

1. A graphic arts easel for the multiple positioning of an image with respect to a workpiece, comprising in combination:

(a) a table having a surface for supporting the workpiece;

(b) a rigid guide rail fixedly secured to said table;

(0) a rigid carriage movably supported on said rigid guide rail for movement in a first direction parallel to said table surface;

(d) a carriage travel stop means movably supported on said rigid guide rail engageable with abutment surfaces on said rigid carriage to limit movement of said carriage along said rigid guide rail, and providing with said carriage and adjustable repeatable travel distance between said carriage and said carrige stop means;

(e) a support movably supported on said carriage for movement in a second direction parallel to said table surface and transverse to said first direction; and

(f) an image holder supported by said support and having an image support surface directed toward said table surface.

2. A graphic arts easel for the multiple positioning of an image with respect to a workpiece, comprising in combination:

(a) a table having a surface for supporting the Workpiece;

(b) a single rigid guide rail fixedly secured to said table and disposed along only one edge thereof;

(c) a rigid elongated carriage movably supported at one end on said rigid guide rail and at the opposite end on said table surface;

, (d) a support movably supported on said rigid carriage for movement in a second direction parallel to said table surface and transverse to said first direction; and

(e) an image holder having an image support surface directed toward said table surface and said image holder being supported by said support.

3. A graphic arts printer for the multiple exposure of a sensitized sheet to an image on a transparency, comprising in combination:

(a) a table having a surface for supporting the sensitized sheet;

(b) a rigid guide rail fixedly secured to said table;

(c) a rigid carriage movably supported on said rigid guide rail for movement in a first direction parallel to said table surface, said carriage comprising a pair of movable rails disposed in spaced relation to each other;

(d) a light source support carried by a first of said movable rails and freely rockable about the axis thereof, said support including a first portion ex tending away from both of said movable rails for engaging the light source, and a second portion extending away from said first of said movable rails and into engagement with the second of said movable rails and limiting the extent of the rocking of said support in only one angular direction, said support being movable on said movable rails in a second direction parallel to said table surface and transverse to said first direction; and

(e) a light source having a transparency support sur- 1 1 face directed toward said table surface and supportable by said support. 4. A graphic arts easel for the multiple positioning of an image with respect to a workpiece, comprising in combination:

said carriage along said guide rail, and providing with (f) an'image holder having an image support surface directed toward said table surface and said image holder being supported by said spring means for normally holding said image support surface away from said table surface and guidin-gly connected to said guide means for movement toward said table 7 surface.

7. A graphic arts printer for the multiple exposure of a sensitized sheet to an image on a transparency, comprising in combination:

(a) a table having a surface for supporting the sensitized sheet;

(b) a rigid guide rail fixedly secured to said table;

(c) a rigid carriage assembly movably supported on said rigid guide rail for movement in a first direction r said carriage an adjustable repeatable travel distance 10 parallel to said table surface; between said carriage and said first stop means; (d) a fixed stop member carried by said table and en- (e) a support movably supported on said rigid carriage gageable by said carriage to define a first origin point: for'movement in a second direction parallel to said (e) a light source support movably supported on said table surface and transverse to said first direction; rigid carriage for movement in a second direction (f) a second stOp means movably supported on said parallel to said table surface and transverse to said rigid carriage and engageable with rigid abutment first direction, said support being engageable with an surfaces on said support to limit movement of said abutment on said carriage at one end of its travel to support along said rigid carriage and providing with define a second origin point; said support an adjustable repeatable travel distance (f) a light source having a transparency support surbetween said support and said second stop means; face directed toward said table surface, said light and source being supported by said support; and

(g) an image holder having an image support surface (g) indicia means on said table surface for locating directed toward said table surface and said image the sensitized sheet on said surface, and said indicia holder being supported by said support. means being so located with respect to said origin 5. A graphic arts printer for the multiple exposure of points as to align one corner area of the sheet bea sensitized sheet to an image on a transparency, comneath said light source. prising in combination: 8. A graphic arts printer for the multiple exposure of (a) a table having a surface for supporting the sensia sensitized sheet to an image on a transparency, comtized sheet; prising in combination:

('b) a rigid guide rail fixedly secured to said table; (a) a table having a surface for supporting the sensi- (c) a rigid carriage movably supported on said rigid tized sheet;

guide rail for movement in a first direction parallel (b) a rigid guide rail fixedly secured to said table; to said table surface; (c) a rigid carriage movably supported on said rigid (d) a light source support movably supported on said 40 tguide rail for movement in a first direction parallel rigid carriage for movement in a second direction to said table surface; parallel to said table surface and transverse to said (d) a carriage travel stop means movably supported first direction, said support including a U-frame havon said rigid guide rail to limit movement of said ing a pair of spaced legs with free ends projecting as carriage along said rigid guide rail; cantilevers and extending in said first direction away (e) a carriage travel adjusting means interconnecting from said carriage and spaced a predetermined dissaid carriage with said carriage stop means to protance above the table surface, and guide means vide a repeatable travel distance between said carmounted on the U-frame legs; riage and carriage stop means;

(e) a light source supported on said support U-frame (f) a; light-source support movably supported on said legs and guided by said support guide means for carriage for movement in a second direction parallel movement toward the sensitized sheet and said light to said table surface and transverse to said first disource including a transparency support surface ex- 'rection; and tending between said U-frame legs and directed to- (g) a light source supportable by said support and havward said table surface. ing a transparency support surface directed toward 6. A graphic arts easel for the multiple positioning of said table surface.

an imagewith respect to a workpiece, comprising in 9. A graphic arts printer for the multiple exposure of combination: a sensitized sheet to an image on a transparency, compris- (a) a table having a surface for supporting the ing in combination:

workpiece; (a) a table having a surface for supporting the sensi- (b) a rigid guide rail fixedly secured to said table; 0 tized sheet;

(c) a rigid carriage movably supported on said fixed .(b) a rigid guide rail fixedly secured to said table;

guide rail for movement in a first direction parallel (c) a rigid carriage assembly movably s PPQ 011 to said table surface; said rigid guide rail for movement in a first direction (d) a first stop means movably supported on said parallel to said table surface;

rigid guide rail and engageable with rigid abutment 5 (d) a first stop means movably supported on said rigid surfaces on said rigid carriage to limit movement of guide rail to limit movement of the carriage along the said carriage along said guide rail, and providing guide rail; with said carriage an adjustable repeatable travel (e) a first step travel adjusting means interconnecting distance between said carriage and said first stop said carriage assembly with said first stop means to means; provide a repeatable travel distance between said car- (e) a support movably supported on said carriage for riage assembly and said first stop means;

movement in a second direction parallel to said table (f) a light source support movably supported on said surface and transverse to said first direction, said rigid carriage for movement in a second direction support including a guide means and a spring means; parallel to said table surface and transverse to said and first direction;

(g) a second stop means movably supported on said rigid carriage to limit movement of said light source support along said rigid carriage;

(h) a second step travel adjusting means interconnecting said second stop means and said light source support to provide a repeatable travel distance between said light source support and said second stop means; and

(i) a light source having a transparency support surface directed toward said table surface and supportable by said support.

10. A graphic art printer for the multiple exposure of a sensitized sheet to an image on a transparency, comprising in combination:

(a) a table having a surface for supporting the sensitized sheet;

(1)) a rigid guide rail fixedly secured to said table;

(c) a rigid carriage assembly movably supported on said rigid guide rail for movement in a first direction parallel to said table surface;

(d) a fixed stop member carried by said table and engageable by said carriage to define a first origin point;

(e) a first stop means movably supported on said rigid guide rail to limit movement of the carriage along the guide rail;

(f) a first step travel adjusting means interconnecting said carriage assembly with said first stop means to provide a repeatable travel distance between said carriage assembly and said first stop means;

(g) a light source support movably supported on said rig-id carriage for movement in a second direction parallel to said table surface and transverse to said first direction; v

(h) a second stop means movably supported on said rigid carriage to limit movement of said light source support along said rigid carriage;

(i) a second step travel adjusting means interconnecting said second stop means and said light source support to provide a repeatable travel distance between said light source support and said second stop means;

(j) a light source having a transparency support surface directed toward said table surface and supportable by said support; and

(k) indicia means on said table surface for locating sensitized sheet on said surface, and said indicia means being so located with respect to said origin points as to align one corner area of the sheet beneath said light source.

- 11. A graphic arts printer for the multiple exposure of a sensitized sheet to an image on a transparency, comprising in combination:

(a) a table having a surface for supporting the sensitized sheet; r

(b) a rigid guide rail fixedly secured to said table;

(c) a rigid carriage assembly movably supported on said fixed guide rail for movement in a first direction parallel to said table surface, said carriage assembly comprising a pair of movable rails disposed in spaced relation to each other;

(d) a, firststop means movably supported on said ,fixed guide rail to limit movement of said carriage along said fixed guide rail;

(e) a first step travel adjusting means interconnecting said carriage assembly with said first stop means to provide a repeatable travel distance between said carriage assembly and first stop means;

(f) a light source support carried by a first of said movable rails and rockable about the axis thereof, said support including a portion extending therefrom into engagement with the second of said movable rails and limiting the rocking of said support in one angular direction, said support being movable on said movable rails in a second direction parallel to said table surface and transverse to said first direction;

(g) a second stop means movably supported on said first movable rail to limit movement of said support on said first movable rail;

(h) a second step travel adjusting means interconnecing said support and said second stop means to provide a repeatable travel distance between said support and second stop means; and

(i) a light source having a transparency support surface directed toward said table surface and supportable by said support.

12, A graphic arts printer for the multiple exposure of a sensitized heet to an image on a transparency, comprising in combination:

(a) a table having a surface for supporting the sensitized sheet;

(b) a rigid guide rail fixedly secured to said ta-ble;

(c) a rigid carriage assembly movably supported on said fixed guide rail for movement in a first direction parallel to said table surface;

(d) a first travel stop means movably supported on said fixed guide rail to limit movement of said carriage along said fixed guide rail;

(e) a first step travel adjusting means interconnecting said carriage assembly with said first stop means to provide a repeatable travel distance between said carriage assembly and first stop means;

(f) a light source support movably supported on said carriage assembly for movement in a second direction parallel to said table surface and transverse to said first direction, said support including a guide means and a spring means; and

(g) a light source having a transparency support surface directed toward said table surface and supported by said spring means for normally holding said transparency surface away from said table surface and guidingly connected to said guide means for movement toward said table surface.

13. A graphic arts printer for the multiple exposure of a sensitized sheet to an image on a transparency, comprising in combination:

(a) a table having a top surface for supporting the sensitized sheet, said top surface having alignmentguide-indicia by which the sensitized sheet is to be located adjacent to one corner of said table surface, said alignment-guide-indicia comprising a grid so arranged as to compensate for various sizes of transparencies and defining X and Y axes;

(b) a rigid guide rail fixedly secured to said table adjacent to one edge thereof and extending parallel to the X-axis;

(c) a fixed stop means attached to to act as a first reference;

(d) a rigid carriage assembly comprising a travel means movably supported on said fixed guide rail for movement thereby along said fixed guide rail parallel to the X-axis, and first lock means connected to said travel means and including actuator means to lock said travel means in a preselected position on said fixed guide rail;

(e) a first travel stop means connected to said fixed guide rail for limiting movement of said carriage assembly on said fixed guide rail;

(f) second lock means connected to said first stop means and including actuator means to stationarily lock said first stop means in a preselected position on said fixed guide rail;

(g) a light source support movably mounted on said carriage and movable therewith parallel to the X- axis;

said fixed guide rail (i) a first step travel adjusting means connected to said 15 carriage assembly and said first stop means to provide a step and repeat distance between said first stop means and said carriage assembly. 14-. A graphic arts printer for the multiple exposure of a sensitized sheet to an image on a transparency, comprising in combination:

(a) a table having a top surface for supporting the sensitized sheet; alignment-guide-indicia by which the sensitized sheet is to be located adjacent to one corner of said table surface, said alignment-guideindicia comprising a grid so arranged as to compensate :for various sizes of transparencies and defining X and Y axes;

(b) a rigid guide rail fixedly secured to said table adjacent to one edge thereof and extending parallel to the X-axis; a fixed stop means attached to said fixed guide rail to act as a first reference;

(c) a rigid carriage assembly movably supported on said fixed guide rail for movement parallel to the X-axis; said carriage having first and second spaced parallel guide rails movable parallel to the X-axis and extending parallel to the Y-axis;

(d) a first travel stop means slidably connected to said fixed guide rail; and first lock means attached to said first stop means to stationarily lock said first stop means in a preselected position on said fixed guide rail;

(e) a second travel stop means slidably connected to said first movable rail, and second lock means to stationarily lock said second stop means in a preselected position on said first movable rail;

(f) a light source support movably mounted on said first movable rail and movable therealong parallel to the Y-axis; and third lock means attached to said support to lock said support in a preselected position on said first movable rail;

(g) a light source comprising: a box enclosing an electrical exposure light means; a switch electrically connected to said light means; said box having a lower translucent transparency support surface corresponding in size to said ta-ble alignment-indicia;

(h) a first step travel adjusting means connected to said carriage assembly and said first stop means to provide a step and repeat distance between said first stop means and said carriage assembly; and

(i) a second step travel adjusting means connected to said support and said second stop means to provide a step and repeat distance between said second stop means and said support.

15. A graphic arts printer for the multiple exposure of a sensitized sheet to an image on a transparency, comprising in combination:

(a) a table having a top surface for supporting the sensitized sheet; alignment-guide-indicia by which the sensitized sheet is to be located adjacent to one corner of said table surface, said alignment-guide-indicia comprising a grid so arranged as to compensate for various sizes of transparencies and defining X and Y axes;

(b) a rigid guide rail fixedly secured to said table adjacent to one edge thereof and extending parallel to the X-axis; a fixed stop means attached to said fixed guide rail to act as a first reference;

() a rigid carriage assembly comprising: a travel means movably supported on said fixed guide rail for movement of said travel means along said fixed guide rail, first lock means connected to said travel means and including actuator means to lock said travel means in a preselected position on said fixed guide rail; first and second spaced parallel movable guide rails rigidly extending from said travel means and being movable therewith, and said first and second movable guide rails extending parallel to the Y-axis;

(d) a first travel stop means connected to said fixed guide rail for limiting movement of said carriage 16 assembly on said fixed guide rail; second lock means connected to said first stop means and including actuator means to stationarily lock said first stop means in a preselected position on said fixed guide rail;

(e) 'a second travel stop'means movably connected to said first movable rail; third lock means connected to said second stop means and including manual actuator means to stationarily lock said second stop means in a preselected position on said first movable rail;

(f) a light source support movably mounted on said first movable rail and movable therealong parallel to the Y-axis; fourth lock means connected to said support and including manual actuator means to lock said support in a preselected position on said first movable rail; and means attached to said support to limit rocking movement of said support about the axis of said first movable rail;

(g) a light source comprising: a box enclosing an electrical exposure light means; a switch electrically connected to said light means; said box having a lower translucent transparency support surface corresponding in size to said table alignment-indicia;

(h) a first step travel adjusting means connected to said carriage assembly and said first stop means to provide a step and repeat distance between said first stop means and said carriage assembly; and

(i) a second step travel adjusting means connected to said support and said second stop means to provide a step and repeat distance between said second stop means and said light source support.

16. A graphic arts printer for the multiple exposure of a sensitized sheet to an image on a transparency, comprising in combination:

(a) atable having a top surface for supporting the sen sitized sheet; align'ment-guide-indicia by which the sensitized sheet is to be located adjacent to one corner of said table surface, said alignment-guide-indicia comprising a grid so arranged as to compensate for various sizes of transparencies and defining X and Y axes;

(b') a rigid guide rail fixedly secured to said table adjacent to one edge thereof and extending parallel to the X-axis; a fixed stop means attached to said fixed guide rail to act as a'first reference;

(c) a rigid carriage assembly comprising: a travel means movably supported on said fixed guide rail for movement of said travel means along said fixed guide rail, first lock means connected to said travel means and including actuator means to lock said travel means in a preselected position on said fixed guide rail; first and second spaced parallel movable guide rails rigidly extending from said travel means andbeing movable therewith, and said first and second movable guide rails extending parallel to the Y-axis;

(d) a first travel stop means connected to said fixed guide rail for limiting movement of said carriage assembly on said fixed guide rail; second lock means connected to said first stop means and including actuator means to stationarily lock said first stop means in a preselected position on said fixed guide rail;

(e) a second travel stop means movably connected to said first movable rail; third lock means connected to said second stop means and including manual actuator means to stationarily lock said second stop means in a preselected position on said first movable rail;

(f) a light source support movably mounted on said first movable rail and movable there along parallel to the Y-axis; fourth lock means connected to said light source support and including manual actuator means'to lock said light source support in a preselected position on said first movable rail; means attached to said light source support to limit rocking movement of said light source support about the axis of the first movable rail; said light source support having a U-frame with a pair of parallel legs being spaced a predetermined distance apart and above the table surface; and a pair of guide pin and spring 18 extending respectively from said U-frame legs; and a pair of springs respectively attached to said U-frame legs; (g) a light source comprising: a box enclosing an electrical exposure light means; a switch electrically means respectively extending from each U-frame connected to said light means; a jewel indicator supleg; ported on said box in optical communication with (g) a light source comprising: a box enclosing an elecsaid light means; said box having a lower translucent trical exposure light means; a switch electrically contransparency support surface corresponding in size nected to said light means; said box having a lower to said table alignment-indicia; a pair of angle frames translucent transparency support surface correspondrespectively adjustably attached to opposite sides of ing in size to said table alignment-indicia; and said said box; means defining a guide port in each angle box supported and guided by said guide pin and frame slidably receptive of said guide pins with said spring means for movement toward said table surangle frames supported on said leaf springs; face; (h) a first step travel adjusting means connected to said (h) a first step travel adjusting means connected to carriage s bl d s id fi t stop eans t prosalrl Carriage assembly and said first P rneans r0 vide a step and repeat distance between said first provide a step and repeat distance between said first stop means and Said carriage assembly; and stop mea s a i ge assembly; and (i) a second step travel adjusting means connected to a second p travel adjusting means c0rlneered re said support and said second stop means to provide said support and said second stop means to provide a step and repeat distance between said second stop means and said light source support.

a step and repeat distance between said second stop means and said light source support. 18. A graphic arts printer for the multiple exposure 17. A graphic arts printer for the multiple exposure of a sensitized sheet to an image on a transparency, comprising in combination:

of a sensitized sheet to an image on a transparency, comprising in combination:

(a) a table having a top surface for supporting the sensitized sheet; alignment-guide-indicia by which the sensitized sheet is to be located adjacent to one (a) a table having a top surface for supporting the sensitized sheet; alignment-guide-indicia by which the sensitized sheet is to be located adjacent to one corner of said table surface, said alignment-guide-indicia C rn r Of said table surface, said allgnrnenl-gnldecomprising a grid so arranged as to compensate the indieis Comprising a grid 80 arranged as to cornvarious sizes of transparencies and defining X and pensate for various sizes of transparencies and de- Y fining X and Y axes; (b) a rigid guide rail fixedly secured to said table adjaa rigid guide rail fixedly secured to said table cent to one edge thereof and extending parallel to adjacent to One edge thereof and eXrendlng Parallel the X-axis; a fixed stop means attached to said fixed to the X-axis; a fixed stop means attached to said id i to t as fi t r fe ence; fiXed guide rail to act as a first reference; (c) a rigid carriage assembly comprising: a travel a rigid Carriage assennbly Comprising! a travel means movably supported on said fixed guide rail means movably supported on said fiXed guide fall for for movement of said travel means along said fixed movem nt f d travel means along said fixed guide 40 guide rail, first lock means connected to said travel rail, first lock means connected to said travel means means d i l di actuator means to l k id a including actuator means to lock said travel travel means in a preselected position on said fixed means in i1 preselected Position on said fixed guide guide rail; first and second spaced parallel movable rail; first and second spaced Parallel movable guide guide rails rigidly extending from said travel means rails rigidly extending from said travel means and d b i bl h ith d id fi t d being movable therewith, and said first and second second movable guide rails extending parallel to the movable guide rails extending parallel to the Y-axis; i

( first travel P means connected to said fixed (d) a first travel stop means connected to said fixed guide rall for limiting IncVernerlt of said Carriage guide rail for limiting movement of said carriage as sembly 011 said fixed guide r second lock means 50. sembly on said fixed guide rail; second lock means C n d to said first p means and including connected to said first stop means and including actuator means t0 stationarily leek said first P actuator means to stationarily lock said first stop means in a preseleeled Position on said fiXed guide means in a preselected position on said fixed guide rail; rail;

. a second trevel p means movably connected to (e) a second travel stop means movably connected to said firs b e rail; third leek rneans eonneered said first movable rail; third lock means connected to to said second st p means d including manual said second stop means and including manual actuaactuator means i statlenarily leek said second step tor means to stationarily lock said second stop means means in a preselected Position on said first movable in a preselected position on said first movable rail; rail; (f) a light source support movably mounted on said a light Source pp movably mounted on said first movable rail and movable therealong parallel first movable rail so as to move therealong parallel t th Y- i f th l k means connected t id to the Y-axis; fourth lock means connected to said support and including manual a tuator means to light source pp and including manual actuator lock said support in a preselected position on said means to lock said light source support in a prefirst movable rail; and means attached to said sup- Seleered Position on said first movable rail; means port to limit rocking movement of said support about extending from one side of said light source supth i f aid fir t ovable rail; port towards said second movable rail and so mov- (g) a light source comprising: a box enclosing an elecably engaging the lower surface the eof as to lim t trical exposure light means; a switch electrically conrocking movement of said light source support about nected to said light means; said box having a lower the axis of said first movable rail; said light source translucent transparency support surface correspondsupport having a U-frame with a pair of paral el ing in size to said table alignment-indicia; legs being spaced a predetermined distance apart (h) a separate transparent alignment device for locatand above said table surface; a pair of guide pins 7 ing the transparency on said transparency support surface in a predetermined position comprising: a plate having indicia defining a second grid having spacing corresponding to that of said grid on said table, and a pair er guide means having a size and (j) a second step travel adjusting means connected to said support and said second stop means to provide a step and repeat distance'between said second stop means and said light source support.

to said table alignment-indicia; a pair of angle frames respectively adjustably attached to opposite sides of said box; means defining a guide port in each angle frame slidably receptive of said guide spacing by which the transparency may be located pins with said angle frames supported on said leaf with reference to a corner of the sensitized sheet; springs;

(i) a first step travel adjusting means connected to (h) a separate transparent alignment device for locatsaid carriage assembly and said first stop means to ing the transparency on said transparency support provide a step and repeat distance between said surface in a predetermined position comprising: a first stop means and said carriage assembly; and plate having indicia defining a second grid having spacing corresponding to that of said grid on said table, and a pair of pins secured to and extending from said plate, said pins having a size and spacing corresponding to that of said guide pins on said 19. A graphic arts printer for the multiple exposure of a sensitized sheet to an image on a transparency, comprising in combination:

(a) a table having a top surface for supporting the sensitized sheet; alignment-guide-indicia by which the sensitized sheet is to be located adjacent to one corner of said table surface, said alignment-guideindicia comprising a grid so arranged as to compensate for various sizes of transparencies and defining X and Y axes;

(b) a rigid guide rail fixedly secured to said table adjacent to one edge thereof and extending parallel to the X-axis; a fixed stop means attached to said fixed guide rail to act as a first reference;

(c) a rigid carriage assembly comprising: a travel U-frame by which the transparency may be located with reference to a corner of the sensitized sheet; (i) a first step travel adjusting means connected to said carriage assembly and said first stop means to provide a step and repeat distance between said first stop means and said carriage assembly; and (j) a second step travel adjusting means connected to said support and said second stop means to provide a step and repeat distance between said second stop means and said light source support. 20. A graphic arts printer for the multiple exposure of a sensitized sheet to an image on a transparency, comprising in combination:

(a) a table having a top surface for supporting the sensitized sheet; alignment-guide-indica by which means movably supported on said fixed guide rail for movement of said travel means along said fixed guide rail, first lock means connected to said travel means and including actuator means to lock said travel means in a preselected position on said fixed guide rail; first and second spaced parallel movable guide rails rigidly extending from said travel means and being movable therewith, and said first and second movable guide rails extending parallel to the Y-axis;

the sensitized sheet is to be located adjacent to one corner of said table surface, said alignmentguide-indicia com-prising a grid so arranged as to compensate for various sizes of transparencies and defining X and Y axes;

(b) a rigid guide rail fixedly secured to said table adjacent to one edge thereof and extending parallel to the X-axis; a fixed stop means attached to said fixed guide rail to act as a first reference;

(0) a rigid carriage assembly comprising: a travel (d) a first travel stop means connected to said fixed block movably supported on said fixed guide rail guide rail for limiting movement of said carriage 'to enable free movement of said travel block along assembly on said fixed guide rail; second lock means said fixed guide rail parallel to the X-axis; rollers connected to said first stop means and including rotatably connected to the travel block and exactuator means to stationarily lock said first stop tending Within said travel block and contacting said melans in a preselected position on said fixed guide {iii/dd 'rtgil arlid su inipotrtingk and guidingesitig rai; I erea ong; rs or: means conn c e (e) a second travel stop means movably connected to to said travel block and including manual actuator said first movable rail; third lock means connected means to stationarily lock said travel block in a to said second stop means and including manual preselected position on said fixed guide rail; a guide actuator means to stationarily lock said second stop Plate y g g g the table adjacent to an melans in a preselected position on said first movable edge cppr'iosit?1 to saidl one elgiige thedreofplfirst airid rai; secon space para e mova e gui e rais Ilgl y (f) a light source support movably mounted on said interconnecting said travel block and said guide first movable rail so as to move therealong parallel I plate and being movable therewith, and said first to the Y-axis; fourth lock means connected to said 5 movable gmde rall extendmg parallel to the light sourcp support and including manual actuator ((1) ad first 1tr'egvel stop means connected to said fixed means to risk said light source support in a regui e rai or limiting movement of said carriage selected position on said first movable rail; means assembly on said fixed guide rail; second lock means extending from one sideof said light source support connected to said first stop means and including towards said second movable rail and so inovably 6O actuator means to stationarily lock said first stop fmgaglng the lower i thel'eofvas t0 llmlt Tockmeans in a preselected position on said fixed guide mg movement of said llght source supportabout the i axis of lslaid first movable rail; Said g Source (e) a second travel stop means movably connected to T g ,avmg a U'frame a of pallauel I said first movable rail; third lock means connected emg spflced a predetermmed. dlstanqe to said second stop means and including manual and above said table surface; a pair of guide pins actuator means to stationarily lock said second stop extendmg respectwely from Sald Uframe legs; and -m ans in a reselected osition on said first movable a pair of springs respectively attached to said U- 1 p p frame legs; rail; p y I (g) a ig t Source comprising: a box enclosing an (f) a llght source support movably mounted on said electrical exposure light means; a switch electrically first movable Tall and movable therealong Parallel contneicted to sgilci light means;la jewel indicator supl -l to the t l l gi lock 1 ctonftlected t0 i por e on sai ox in optica communi atio wit suppor an incu lng manna ac ua or means 0 said light means; said box having a lower translucent lock said support in a preselected position on said transparency support surface corresponding in size 75. first movable rail; and means attached to said support 21 to limit rocking movement of said support about the axis of said first movable rail;

(g) a light source comprising: a box enclosing an electrical exposure light means; a switch electrically connected to said light means; said box having a lower translucent transparency support surface corresponding in size to said table alignment-indicia;

(h) a first step travel adjusting means connected to said carriage assembly and said first stop means to provide a step and repeat distance between said first stop means and said carriage assembly; and

(i) a second step travel adjusting means connected to said support and said second stop means to provide a step and repeat distance between said second stop means and said light source support.

21. A graphic arts printer for the multiple exposure of a sensitized sheet to an image on a transparency, comprising in combination:

(a) a table having a top surface for supporting the sensitized sheet; alignment-guide-indicia by which the sensitized sheet is to be located adjacent to one corner of said table surface, said alignmentguide-indicia comprising a grid so arranged as to compensate for various sizes of transparencies and defining X and Y axes;

(b) a rigid guide rail fixedly secured to said table adjacent to one edge thereof and extending parallel to the X-axis; a fixed stop means attached to said fixed guide rail to act as a first reference;

(c) a rigid carriage assembly comprising: a travel block movably support-ed on said fixed guide rail to enable free movement of said travel block along said fixed guide rail parallel to the X-axis; rollers rotatably connected to the travel block and extending within said travel block and contacting said fixed guide rail and supporting and guiding said travel block therealong; first lock means connected to said travel block and including manual actuator means to stationarily lock said travel block in a preselected position on said fixed guide rail; a guide plate movably engaging the table adjacent to an edge opposite to said one edge thereof; first and second spaced parallel movable guide rails rigidly interconnecting said travel block and said guide plate and being movable therewith, and said first movable guide rail extending parallel to the Y-axis;

(d) a first travel stop means connected to said fixed guide rail for limiting movement of said carriage assembly on said fixed guide rail; second lock means connected to said first stop means and including actuator means to stationarily lock said first stop means in a preselected position on said fixed guide rail;

(e) a second travel stop means movably connected to said first movable rail; third lock means connected to said second stop means and including manual actuator means to stationarily lock said second stop means in a preselected position on said first movable rail;

(f) a light source support movably mounted on said first movable rail so as to move ther'ealong parallel to the Y-axis; fourth lock means connected to said light source support and including manual actuator means to lock said light source support in a preselected position on said first movable rail; means extending from one side of said light source support towards said second movable rail and so movably engaging thelower surface thereof as to limit rocking movement of said light source support about the axis of said first movable rail; said light source support having a U-frame with a pair of parallel legs being spaced a predetermined distance apart and above said table surface; a pair of guide pins extending respectively from said U-frame legs; and

22 a pair of springs respectively attached to said U- frame legs;

(g) a light source comprising: a box enclosing an electrically exposure light means; a switch electrically connected to said light means; a jewel indicator supported on said box in optical communication with said light means; said box having a lower translucent transparency support surface corresponding in size to said table alignment-indicia; a pair of angle frames respectively adjustably attached to opposite sides of said box; means defining a guide port in each angle frame slidably receptive of said guide pins with said angle frames supported on said leaf springs;

(11) a first step travel adjusting means connected to said carriage assembly and said first stop means to provide a step and repeat distance between said first stop means and said carriage assembly; and

(i) a second step travel adjusting means connected to said support and said second stop means to provide a step and repeat distance between said second stop means and said light source support.

22. A graphic arts printer for the multiple exposure of a sensitized sheet to an image on a transparency, comprising in combination:

(a) a table having a top surface for supporting the sensitized sheet; alignment-guide-indicia by which the sensitized sheet is to be located adjacent to one corner of said table surface, said alignmentguide-indicia comprising a grid so arranged as to compensate for various sizes of transparencies and defining X and Y axes;

(b) a rigid guide rail fixedly secured to said table adjacent to one edge thereof and extending parallel to the X-axis; a fixed stop means attached to said fixed guide rail to act as a first reference;

(0) a rigid carriage assembly comprising: a travel block movably supported on said fixed guide rail to enable free movement of said travel block along said fixed guide rail parallel to the X-axis; rollers rotatably connected to the travel block and extending within said travel block and contacting said fixed guide rail and supporting and guiding said travel block therealong; first lock means connected to said travel block and including manual actuator means to stationarily lock said travel block in a preselected position on said fixed guide rail; a guide plate movably engaging the table adjacent to an edge opposite to said one edge thereof; first and second spaced parallel movable guide rails rigidly interconnecting said travel block and said guide plate and being movable therewith, and said first movable guide rail extending parallel to the Y-axis;

(d) a first travel stop means connected to said fixed guide rail for limiting movement of said carriage assembly on said fixed guide rail; second lock means connected to said first stop means and including actuator means to stationarily lock said first stop means in a preselected position on said fixed guide rail;

(e) a second travel stop means movably connected to said first movable rail; third lock means connected to said second stop means and including manual actuator means to stationarily lock said second stop means in a preselected position on said first movable rail;

(f) a light source support comprising: a second travel block movably mounted on said first movable rail to move therealong parallel to the Y-axis; second rollers rotatably connected to said second travel block and extending within said second travel block and contacting said first movable rail and supporting and guiding said second travel block therealong; fourth lock means connected to said second travel block to lock said second travel block in a preselected position on said first movable rail; and

means attached to said second travel block to limit rocking movement of said second travel block about the axis of said first movable rail;

(g) a light source comprising: a box enclosing an electrical exposure light means; a switch electrically connected to said light means; said box having a lower translucent transparency support surface corresponding in size to said table alignment-indicia;

(h) a first step travel adjusting means connected to said carriage assembly and said first stop means to provide a step and repeat distance between said first stop means and said carriage assembly; and

(i) a second step travel adjusting means connected to said support and said second stop means to provide a step and repeat distance between said second stop means and said light source support.

23. A graphic arts printer for the multiple exposure of a sensitized sheet to an image on a transparency, comprising in combination:

(a) a table having a top surface for supporting the sensitized sheet; alignment-guide-indicia by which the sensitized sheet is to be located adjacent to one corner of said table surface, said alignment-guide-indicia comprising a grid so arranged as to compensate for various sizes of transparencies and defining X and Y axes;

(b) a rigid guide rail fixedly secured to said table adjacent to one edge thereof and extending parallel to the X-axis; a fixed stop means attached to said fixed guide rail to act as a first reference;

() a rigid carriage assembly comprising: a travel block movably supported on said fixed guide rail to enable free movement of said travel block along said fixed guide rail parallel to the X-axis; rollers rotatably connected to the travel block and extending within said travel block and contacting said fixed guide rail and supporting and guiding said travel block therealong; first lock means connected to said travel block and including manual actuator means to stationarily lock said travel block in a preselected position on said fixed guide rail; a guide plate movably engaging the table adjacent to an edge opposite to said one edge thereof; first and second spaced parallel movable guide rails rigidly interconnecting said travel block and said guide plate and being movable therewith, and said first movable guide rail extending parallel to the Y-axis;

(d) a first travel stop means connected to said fixed guide rail for limiting movement of said carriage assembly on said fixed guide rail; second lock means connected to said first stop means and including actuator means to stationarily lock said first stop means in a preselected position on said fixed guide rail;

(e) a second travel stop means movably connected to said first movable rail; third lock means connected to said second stop means and including manual actuator means to stationarily lock said second stop means in a preselected position on said first movable rail;

(f) a light source support comprising: a second travel block movably mounted on said first movable rail to move therealong parallel to the Y-axis; second rollers rotatably connected to the second travel block and extending within said second travel block and contacting said first movable rail and supporting and guiding said second travel block therealong; fourth lock means connected to said second travel block to lock said second travel block in a preselected position on said first movable rail; a guide rod extending from one side of said second travel block towards said second movable rail and so movably engaging the lower surface thereof as to limit rocking movement of said second travel block about the axis of said first movable rail; a U-frame attached to said second travel block and having a pair of parallel legs extending from a side opposite to said one side of said second travel block and being spaced a predetermined distance apart and above said table surface; a pair of guide pins respectively extending perpendicularly from said U-frame legs; and a pair of spring means respectively attached to said U-frame leg;

(g) a light source comprising: a box enclosing an electrical exposure light means; a switch electrically connected to said light means; said box having a lower translucent transparency support surface corresponding in size to said table alignment-indicia; and said box supported and guided by said guide pin and spring means for movement toward said table surface;

(h) a first step travel adjusting means connected to said carriage assembly and said first stop means to provide a step and repeat distance between said first stop means and said carriage assembly; and

(i) a second step travel adjusting means connected to said support and said second stop means to provide a step and repeat distance between said second stop means and said light source support.

24. A graphic arts printer for the multiple exposure of a sensitized sheet to an image on a transparency, com prising in combination:

(a) a table having a top surface for supporting the sensitized sheet; alignment-guide-indicia by which the sensitized sheet is to be located adjacent to one corner of said tab-1e surface, said alignment-guideindicia comprising a grid so arranged as to compensate for various sizes of transparencies and defining X and Y axes;

(b) a rigid guide rail fixedly secured to said table adjacent to one edge thereof and extending parallel to the X-axis; a fixed stop means attached to said fixed guide rail to act as a first reference;

(c) a rigid carriage assembly comprising: a travel means movably supported on said fixed guide rail for movement of said travel means along said fixed guide rail, first lock means connected to said travel means and including actuator means to lock said travel means in a preselected position on said fixed guide rail; first and second spaced parallel movable guide rails rigidly extending from said travel means and being movable therewith, and said first and second movable guide rails extending parallel to the Y-axis;

(d) a first travel stop means connected to said fixed guide rail for limiting movement of said carriage assembly on said fixed guide rail; second lock means connected to said first stop means and including actuator means to stationarily lock said first stop means in a preselected position on said fixed guide rail;

(e) a second travel stop means movably connected to said first movable rail; third lock means connected to said second stop means and including manual actuator means to stationarily lock said second stop means in a preselected position on said first movable rail;

(f) a light source support movably mounted on said first movable rail and movable therealong parallel to the Y-axis; fourth lock means connected to said support and including manual actuator means to lock said support in a preselected position on said first movable rail; and means attached to said support to limit rocking movement of said support about the axis of said first movable rail;

(g) a light source comprising: a box enclosing an electrical exposure light means; a switch electrically connected to said light means; said box having a lower translucent transparency support surface corresponding in size to said table alignment-indicia;

(h) a first step travel adjusting means comprising: a

first rod connected to said travel means and extending parallel to said fixed guide rail; a first apertured bracket extending from said first stop means and through the apertures of which said first rod extends;

and first nut means adjustably fixed on said first rod to limit relative movement between said carriage assembly and said first stop means when only one of said first and second lock means is released; and

(i) a second step travel adjusting means comprising:

26 ing parallel to said fixed guide rail; a first apertured bracket extending from said first stop means and through the apertures of which said first rod extends; and first nut means adjustably fixed on said first rod to limit relative movement between said carriage assembly and said first stop means when only one of said first and second lock means is released; and (i) a second step travel adjusting means comprising: a second rod connected to said light source support and extending parallel to said first movable rail; a second apertured bracket extending from said second stop means and through the aperture of which said second rod extends; and second nut means adjustably fixed on said second rod to limit relative 25. A graphic arts printer for the multiple exposure of a sensitized sheet to an image on a transparency, comprising in combination:

(a) a table having a top surface for supporting the movement between said second stop means and said light source support when only one of said third and fourth lock means is released.

26. A graphic arts printer for the multiple exposure of sensitized sheet; alignment-guide-indicia by which the sensitized sheet is to be located adjacent to one corner of said table surface, said alignment-guideindicia comprising a grid so arranged as to compensate for various sizes of transparencies and defining X and Y axes;

a sensitized sheet to an image on a transparency, comprising in combination:

(a) a table having a top surface for supporting the sensitized sheet; alignment-guide-indicia by which the sensitized sheet is to be located adjacent to one corner of said table surface, said alignment-guide- (b) a rigid guide rai-l fixedly secured to said table indicts comprising a grid 50 arranged as to adjacent to one edge thereof and extending parallel Pehsate for Various siZes of trahsParencies definto the X-axis; a fixed stop means attached to said ing X and Y axes; fixed guide rail to act a a fir t ref r (b) a rigid guide rail fixedly secured to said table adja- (c) a rigid carriage assembly comprising: a travel cent to one edge thereof and extending Pelralle1 t0 means movably supported on said fixed guide rail the a fiXed p means attached to said fiXed for movement of said travel means along said fixed guide rail to act as a first reference; guide rail, first lock means connected to said travel a rigid carriage assembly comprising: a travel bleck means and including actuator means to lock said movably supported on said fixed guide rail t0 enable travel means in a preselected position on said fixed free movement of said travel block along said fixed guide rail; first and second spaced parallel movable guide rail Parallel to the rollers rotatahly guide rails rigidly extending from said travel means Connected to the travel block and eXtehdihg Within and being movable therewith, and said first and secsaid travel block and contacting said fixed guide ond movable guide rails extending parallel to the rail and supporting and guiding said travel hleek -axis; therealong; first lock means connected to said travel (d) a first travel stop mean o t d t id fi d block and including manual actuator means to staguide rail for limiting move t f id carriage tionarily lock said travel block in a preselected posiassembly on said fixed guide rail; second lock means tion on said fixed guide a guide Plate movably connected to Said first stop means and including actuengaging the table adjacent to an edge pp to ator means to stationarily lock said first stop means said one edge thereof; first and second spaced Parallel in a p selec ed position on said fixed guide rail; movable guide rails rigidly interconnecting said travel (e) a second travel stop means movably connected to block and said guide Plate and being movable theresaid first movable rail; third lock means connected With, and said first Kiel/able guide rail extending to said second stop means and including manual actu- Parallel to the ator means to stationarily lock said second stop first travel p means eonheeted to said fixed means in a preselected position on said first movable guide rail for limiting movement of said Carriage rail; assembly on said fixed guide rail; second lock means (f) a light source support movably mounted on said cOrlrleeted to said first P means and including first movable rail and movable therealong parallel actuator means to stationarily 100k said first P to the Y-axis; fourth lock means connected to said means in a preselected position or! said fixed guide light source support and including manual actuator rail; means to lock said light source support in a prea second travel P means movably Connected to selected position on said first movable rail; means said first movable rail; third leek means Connected attached to said light source support to limit rocking to said second p means and including manual movement of aid light ourge Support about h actuator means to stationarily lock said second stop axis of the first movable rail; said light source supmeans in a preselected Position on said first movable port having a U-frame with a pair of parallel legs rail; being spaced a predetermined distance apart and a light source pp movably mounted 011 said above the table urface; nd a i f id i d first movable rail and movable therealong parallel spring means respectively t di f h U to the Y-axis; fourth lock means connected to said frame leg; support and including manual actuator means to (g) a light source comprising: a box enclosing an elec- 106k said support in a @reseleeted Position on said trical exposure light means; a switch electrically confirst movable rail; and means attached to said P" nected to said light means; said box having a lower P to limit rocking movement of said pp about translucent transparency support surface correspondthe axis of said first movable rail; ing in size to said table alignment-indicia; and said a light source Comprising: hex enclosing an box supported and guided b id id i and electrical exposure light means; a switch electrically spring means for movement toward said table sur- Connected to said light means; said hOX havhlg a face; lower translucent transparency support surface cor- (h) a first step travel adjusting means comprising: a responding in size to said table alignment-indicia;

first rod connected to said travel means and extend- (h)' a first step travel adjusting means comprising:

a first rod connected to said first travel block and extending parallel to said fixed guide rail; a first apertured bracket extending from said first stop means and through the aperture of which said first rod extends; and first nut means adjustably fixed on said first rod to limit relative movement between said carriage assembly and said first stop means when only one of said first and second lock means is released; and

(i) a second step travel adjusting means comprising: a second rod connected to said light source support and extending parallel to said first movable rail; a second apertured bracket extending from said second stop means and through the aperture of which said second rod extends; and second nut means adjustably fixed on said second rod to limit relative movement between said second stop means and said light source support when only one of said third and fourth lock means is released.

27. A graphic arts printer for the multiple exposure of a sensitized sheet to an image on a transparency, comprising in combination:

(a) a table having a top surface for supporting the sensitized sheet; alignment-guide-indicia by which the sensitized sheet is to be located adjacent to one corner of said ta'ble surface, said alignment-guideindicia comprising a grid so arranged as to compensate for various sizes of transparencies and defining X and Y axes;

(b) a rigid guide rail fixedly secured to said table adjacent to one edge thereof and extending parallel to the X-aXis; a fixed stop means attached to said fixed guide rail to act as a first reference;

(c) a rigid carriage assembly comprising: a travel block movably supported on said fixed guide rail to enable free movement of said travel block along said fixed guide rail parallel to the X-axis; rollers rotatably connected to the travel block and extending within said travel block and contacting said fixed guide rail and supporting and guiding said travel block therealong; first lock means connectedto said travel block and including manual actuator means to stationarily lock said travel block in a preselected position on said fixed guide rail; a guide plate movably engaging the table adjacent to an edge opposite to said one edge thereof; first and second spaced parallel movable guide rails rigidly interconnecting said travel block and said guide plate and being movable therewith, and said first movable guide rail extending parallel to the Y-axis;

(d) a first travel stop means connected to said fixed guide rail for limiting movement of said carriage assembly on said fixed guide rail; second lock means connected to said first stop means and including actuator means to stationarily lock said first stop means in a preselected position on said fixed guide rail;

(e) a second travel stop means movably connected to said first movable rail; third lock means connected to said second stop means and including manual actuator means to stationarily lock said second stop means in a preselected position on said first movable rail;

(f) a light source support comprising: a second travel block movably mounted on said first movable rail to move therealong parallel to the Y-axis; second rollers rotatabiy connected to the second travel block and extending within said second travel block and contacting said first movable rail and supporting and 2% said first movable rail; a U-frame attached to said second travel block and having a pair of parallel legs extending from a side opposite to said one side of said second travel block and being spaced a predetermined distance apart and above said table surface; a pair of guide pins respectively extending perpendicularly from said U-frame legs; and a pair of spring means respectively attached to said U- frame leg;

(g) a light source comprising: a box enclosing an electrical exposure light means; a switch electrically connected to said light means; said box having a lower translucent transparency support surface corresponding in size to said table alignment-indicia; and said box supported and guided by said guide pin and spring means for movement toward said table surface;

(h) a first step travel adjusting means comprising: a

first rod connected to said first travel block and extending parallel to said fixed guide rail; a first apertured bracket extending from said first stop means and through the aperture of which said first rod extends; and first nut means adjustably fixed on said first rod to limit relative movement between said carriage assembly and said first stop means when only one of said first and second lock means is released; and

(i) a second step travel adjusting means comprising:

a second rod connected to said second travel block and extending parallel to said first movable rail; a second apertured bracket extending from said second stop means and through the aperture of which said second rod extends; and second nut means adjustably fixed on said second rod to limit relative movement between said second stop means and said light source support when only one of said third and fourth lock means is released.

28. A graphic arts printer for the multiple exposure of a sensitized sheet to an image on a transparency, comprising in combination:

guiding said second travel block therealong; fourth ment of said second travel block about the axis of I (a) a table having a top surface for supporting the sensitized sheet; alignment-guide-indicia by which the sensitized sheet is to be located adjacent to one corner of said table surface, said alignment-guide-indicia comprising a grid so arranged as to compensate for various sizes of transparencies and defining X and Y axes;

(b) a rigid guide rail fixedly secured to said table adjacent to one edge thereof and extending parallel to the X-axis; a fixed stop means attached to said fixed guide rail to act as a first reference;

(c) a rigid carriage assembly comprising: a travel block movably supported on said fixed guide rail to enable free movement of said travel block along said fixed guide rail parallel to the X-axis; rollers rotatably connected to the travel block and extending within said travel block and contacting said fixed guide rail and supporting and guiding said travel block therealong; first lock means connected to said travel block and including manual actuator means to stationarily lock said travel block in a preselected position on said fixed guide rail; a guide plate movably engaging the table adjacent to an edge opposite to said one edge thereof; first and second spaced parallel movable guide rails rigidly interconnecting said travel block and said guide plate and being movable therewith, and said first movable guide rail extending parallel to the Y-axis;

(d) a first travel stop means connected to said fixed (e) a second travel stop means movably connected to 'said first movable rail; third lock means connected to said second stop means and including manual actuator means to stationarily lock said second stop means in a preselected position on said first movable rail; 7

(f) a light source support movably mounted on said first movable rail and movable therealong parallel to the Y-axis; fourth lock means connected to said support and including manual actuator means to lock said support in a preselected position on said means in a preselected position on said first movable rail;

(f) a light source support comprising: a second travel block movably mounted on said first movable rail to move therealong parallel to the Y-axis; second rollers rotatably connected to said second travel block and extending within said second travel block and confirst movable rail; and means attached to said sup- 1O fading said first movable fail and Supporting and port t li it ki movement of id support guiding said second travel block therealong; fourth b t th i f id fi bl il; lock means connected to said second travel block to (g) a light ource comprising; a box enclosing an elec- 100k said second travel blOCk in a preselected PCS]..- trical exposure light means; a switch electrically con- 5011 on said first movable rail; and means attached to nected to id li h means; id b h i a lower said second travel block to limit rocking movement translucent transparency support surface correspondof Said Second travel block about the axis of Said ing in size to said table alignment-indicia; first movable Tail;

(h) a separate transparent alignment device for locatlight Source Fompfisingi a 9 finclosillg an 6160" i h transparency on i transparency Support trlcal exposure l ght means; a switch electrically consurface in a predetermined position comprising: a nected to Sald llght means; Sald bOX having a lower plate having indicia defining a second grid having P f f transparency QPP I F FQ P spacing corresponding to that of said grid on said mg 111 $126 to 531d table ah gnmentmd1c 1a; table, and a pair of guide means having a size and (h) a separate transparent alignment device for locatspacing by which the transparency may be located mg the t p r ncy I} ald transparency support with reference to a corner of the sensitized sheet; surface In a Predetermmed Posmon compnsmg: a and plate having indicia defining a second grid having (i) a first step travel adjusting means comprising: a Spacing correspPnding that of Said, grid said first rod connected to said first travel block and extabla and a pan ofguide means having a size and tending parallel to said fixed guide rail, a first aperspficmg by Whlch the transparency ma be located tured bracket extending from said first stop means wlth reference to a comer P the Sensmzed h j and through the aperture of Which said first rod ex- (1) a first Step travel ad] st1ng means compnsmg: a tends; and first nut means adjustably fixed on said first rod connected to said first travel block and exfirst rod to limit relative movement between said tendmg parallel to sa,1d fixed l fall; a first aper carriage assembly and said first stop means When fined bracket extendmg from 9 Stop means only one of said first and second lock means is reand hrough the aperture of W h1ch sald first leased tends; and first nut means ad ustably fixed on sa d 29. A graphic arts printer for the multiple exposure of first. rod to 1mm relatlve. movement between sald a sensitized sheet to an image on a transparency, comcarnage assemply and Sald first Stop means .when prising in combination: only one of said first and second lock means rs re- (a) a table having a top surface for supporting sensileased; and tized sheet; alignment-guide-indicia by which the (J) a second step travel adjustlpg means compnsmg sensitized sheet is to be located adjacent to one cora second q Connected to i second travel 9 net of said table surface, said alignment-guide-inand extending g g i to Said fi ig Tall g dicia comprising a grid so arranged as to compensate Second aperturg i elitendmg g i for various sizes of transparencies and defining X and Stop means an t mug t e aperture 0 w Y axes; second rod extends; and second nut means ad ust- (b) a rigid guide rail fixedly secured to said table adably fixed on Second rod to hmlt relatwe.mqve jacent to one edge thereof and extending parallel to ment between saldhsecondl stop mains fig 5 g g the X-axis; a fixed stop means attached to said fixed source Support W en on y one 0 Sal t u an guide rail to act as a first reference;

fourth lock means is released.

(c) a rigid carriage assembly comprising: a travel block A graphic arts printer for the multlp 1e exposure of movably supported on said fixed guide rail to enable free movement of said travel block along said fixed guide rail parallel to the X-axis; rollers rotatably a sensitized sheet to an image on a transparency, comprising in combination:

(a) a table having a top surface for supporting the connected to the travel block and extending Within sensitizeli. sheet; allgnment-guidedndicia by which said travel block and contacting said fixed guide rail the g qg gg fi g gggf g f E and supporting and guiding said travel block theregf f a C T d 'g ealong; first lock means connected to said travel block P g ar as g f 1aniincliiiding nliailualkactuator melans to stationarily i g g zigg $1268 0 ransparencles an e nmg 0c sai trave 0c in a prese ected position on said fixed guide rail; 3 guide plate movably engaging a i gmde 2 12 F g gi fi i the table adjacent to an edge opposite to said one lace; 0 e be ereo an ex en Para P edge thereof; first and second spaced parallel movto t e x' a fixed stop means attached to sand able guide rails rigidly interconnecting said travel fixed 5 a act as i feferFljlcei. 1 blolck anal saidd glide Plate gird beilg moillable therenilgclg fiovggg zigpgrsg on sig gg iidz rgi l fo wit an sai rst mova e ui e rai extend ll l to h Y i g mg enable free movement of said travel block along said (d) a first travel stop means connected to said fixed 'fiXed fail Parallel to the rollers guide rail for limiting movement of said carriage asy coflnected to the travel block and extending sembly on said fixed guide rail; second lock me Within said travel block and contacting said fixed connected to said first stop means and including acguide rail Supporting and guiding Said travel tuator means to stationarily lock said first stop means block therealong; first lock means connected to said in a preselected position on said fixed guide rail; travel block and including manual actuator means to (e) a second travel stop means movably connected to 7 stationarily lock said travel block in a preselected position on said fixed guide rail; a guide plate movably engaging the table adjacent to an edge opposite to said one edge thereof; first and second spaced parallel movable guide rails rigidly interconnecting said travel block and said guide plate and being movable therewith, and said first movable guide rail extending parallel to the Y-axis;

32' and extending parallel to said first movable rail; a second apertured bracket extending from said second stop means and through the aperture of which said second rod extends; and second nut means adjustably fixed on said second rod to limit relative movement between :said second stop means and said light source support when only one of said third and fourth lock means is released. 31. A graphic arts printer for the multiple exposure of a sensitized sheet to an image on a transparency, comprising in combination:

(a) a table having a top surface for supporting the sensitized sheet; alignment-guide-indicia by which the sensitized sheet is to be located adjacent to one (d) a first travel stop means connected to said fixed guide rail for limiting movement of said carriage assembly on said fixed guide rail; second lock means 1 connected to said first stop means and including actuator means to stationarily lock said first stop means in a preselected position on said fixed guide rail;

(e) a second travel stop means movably connected to carriage assembly and said first stop means when only one of said first and second lock means is released; and

(j) a second step travel adjusting means comprising:

a second rod ponnpcted to said second travel block said first movable rail; third lock means connected cornerrof said table surface, said alignment-guideto said second stop means and including manual acindicia comprising a grid so arranged as to compentuator means to stationarily lock said second stop sate for various sizes of transparencies and defining means in a preselected position on said first 'rnov- X andY axes; able rail; (b) a rigid guide rail fixedly secured to said table adja- (f) alight source support comprising: a second travel 0 cent to one edge thereof and extending parallel to block movably mounted on said first movable rail the X-axis, said fixed guide rail having a relatively to move therealong parallel to the Y-axis; second fiat top surface extending for a major portion of the rollers rotatably connected to the second travel block length thereof, said fixed guide rail extending suband extending within said second travel block and stantially the length of said table; a fixed stop washer contacting said first movable rail and supporting and attached to said fixed guide rail to act as a reference; guiding said second travel block therealong; fourth (c) a rigid carriage assembly comprising: a first travel lock means connected to said second travel block block movably connected to said fixed guide rail to lock said second travel block in a preselected posi to enable free movement of said first travel block tion on said first movable rail; a guide rod extending along said fixed guide rail parallel to the X-axis; offfrom one side of said second travel block towards set rollers rotatably connected to said first travel said second movable rail and so movably engaging block and extending within said first travel block the lower surface thereof as to limit rocking moveand contacting a curved surface of said fixed guide ment of said second travel block about the axis of rail and supportingand guiding said first travel block said first movable rail; a U-frame attached to said therealohg; fi t lock m a s C nn ct d t aid first second travel block and having a pair of parallel legs a l block and inslllding a first brake shOe memextending from a side o o ite to aid o e id of ber positioned within said first travel block facing said second travel block and being spaced 3 presaid flat surface of said fixed guide rail, and includdetermined distance apart and above said table sur g manual actuator m ns 0 p ative n aid first race; a pair of guide pins respectively extending perbrake shoe member as to stationarily lock said first pendicularly from said U-frame legs; and a pair of travel block in a preselected position on said fixed spring means respectively attached to said U-frame rigid guide rail, 3 guide Plate movably Connected to leg; said table adjacent an edge opposite said one edge {g) a light source comprising: a box enclosing an electherehf; first and second spaced Parallel movable trical exposure light means; a switch electrically guide rails g y ihtsrcorlhestifig said travel b10014 connected to said light means; a jewel indicator supand said guide Plate and being movable therewith; ported on said box in optical communication with said first movable guide rafi extending Pttrafis1 to said light means; said box having a lower translucent the Y-aXis and having a relatively fiat p stlrtase transparency support surface corresponding in size extending for a major Portion of the length thereof; to said table alignment-indicia; a pair of angle'frames a t t p block movably ftohhscted to said respectively adjustably attached to opposite sides of fixed guide Tall for movement of sald first p block said box; means defining a guide port in each angle along said fixed guide rail Parallel to the frame slidably receptive of said guide pins with said second lock means Connected to said first p block angle frames supported on id l f i and including a second brake shoe member'positioned (h) a separate transparent alignment device for locat- Withih t P block f g said fiat surface ing the transparency on said transparency support sald fixed gfilde h and lhchldlhg manual actuasurface in a predetermined position comprising: a tor means so operatlve on sald second brake shoe as plate h i i di i d fini a Second grid'hgving to stationarily lock said first stop block in a pre-sespacing corresponding to that of said grid on said tested Position on said fixed guide rail; table, and a pair of pins secured to and extending f second travel hlosk v y Connected t f id l id i h i a i and Spacing said first movable guide ra1l for movement of said corresponding to that of said guide pins on said sesohd p block 5 sald first movable glllde U-frame by which the transparency may be located r811 Parafie1 t0 the second lock means 9 with reference to a corner of the sensitized sheet; nected to said second stop m a itfcludtng a thlrd (i) a first step travel adjusting means comprising: a brake shoe msmbefipositlofied Wlthlh s sscohd first rod connected to said first travel block and exstop block tsclhg s first movable gulde r311 fi tending parallel to said fixed guide rail; a first apersurtatfe t Including manual actltator s operatlYe t d b k extending fr i fi t stop means on said third brake shoe as to stationarily lock said and through the aperture of which said first rod exsecond p block in a preselected Position on said tends; and first nut means adjust ably fixed on said first movable guide rail; first rod to limit relative movement between said (f) a light source support comprising a second travel block movably connected to said first movable guide rail for movement of said second travel block along said first movable rail parallel to the Y-axis; second offset rollers rotatably connected tosaid second travel block and extending within said second travel 

1. A GRAPHIC ARTS EASEL FOR THE MULTIPLE POSITIONING OF AN IMAGE WITH RESPECT TO A WORKPIECE, COMPRISING IN COMBINATION: (A) A TABLE HAVING A SURFACE FOR SUPPORTING THE WORKPIECE; (B) A RIGID GUIDE RAIL FIXEDLY SECURED TO SAID TABLE; (C) A RIGID CARRIAGE MOVABLY SUPPORTED ON SAID RIGID GUIDE RAIL FOR MOVEMENT IN A FIRST DIRECTION PARALLEL TO SAID TABLE SURFACE; (D) A CARRIAGE TRAVEL STOP MEANS MOVABLY SUPPORTED ON SAID RIGID GUIDE RAIL ENGAGEABLE WITH ABUTMENT SURFACES ON SAID RIGID CARRIAGE TO LIMIT MOVEMENT OF SAID CARRIAGE ALONG SAID RIGID GUIDE RAIL, AND PROVIDING WITH SAID CARRIAGE AND ADJUSTABLE REPEATABLE TRAVEL DISTANCE BETWEEN SAID CARRIAGE AND SAID CARRIGE STOP MEANS; (E) A SUPPORT MOVABLY SUPPORTED ON SAID CARRIAGE FOR MOVEMENT IN A SECOND DIRECTION PARALLEL TO SAID TABLE SURFACE AND TRANSVERSE TO SAID FIRST DIRECTION; AND (F) AN IMAGE HOLDER SUPPORTED BY SAID SUPPORT AND HAVING AN IMAGE SUPPORT SURFACE DIRECTED TOWARD SAID TABLE SURFACE. 